The present invention relates to redundancy circuit and method, and more particularly, redundancy circuit and method of a ferroelectric memory device for software-wise repairing a failed normal memory cell by using a redundancy memory cell.
In realizing a memory device, when some cells of arrayed cells are failed, it is wasteful to remove the whole of a memory device. Thus, a memory device, such as DRAM(dynamic random access memory), generally includes a redundancy circuit for repairing a failed normal memory cell by using a redundancy memory cell.
A redundancy circuit of a ferroelectric memory device, such as FRAM(ferroelectric random access memory), has employed a traditional DRAM redundancy circuit. As a traditional redundancy circuit employs a hardware-wise method, i.e., the circuit cuts the repair fuse involved in a decoder, the circuit cannot repair the memory device which a package has been completed. Namely, when fail is founded at a burn-in test after packaging, the failed chip cannot be repaired, so the chip must be burned up. Accordingly, the yield of a memory device is greatly decreased.